There have conventionally been proposed various audio apparatuses that allow a voice conference by connecting to a conference room at a remote location via a communication network (for example, see PLT 1). Such an audio apparatus is provided with a microphone and a speaker and, when being placed on a table or the like in a conference room, picks up a sound in the room with the microphone and transmits the sound as a transmission audio signal to another audio apparatus (the other party's audio apparatus) in the other party's conference room, as well as outputting, from the speaker, a received audio signal (a sound in the other party's conference room) transmitted from the other party's audio apparatus. As the speaker, a dynamic speaker is typically used.
Also, for example, a conventional television receiver (hereinafter, simply referred to as a “TV”) generates a sound from a speaker provided to the TV. As the speaker of the conventional TV, the dynamic speaker is typically used and, for example, PLT 2 describes a TV using the dynamic speaker.
Further, for example, a conventional projection apparatus generates a sound from a speaker provided thereto. As the speaker of the conventional projection apparatus, the dynamic speaker is typically used. For example, PLT 3 describes a vibration generation apparatus having a structure of the dynamic speaker provided with a magnet, a voice coil, a diaphragm, and a casing for accommodating these components. Frequency characteristics of the sound generated from the dynamic speaker is affected by a size of the dynamic speaker. For example, in order to reproduce a low-pitched sound, a large dynamic speaker is required.